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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a6e2de66b08a921ed68ffbda21ef3121e21bb7493a8397cddea55d3df52ebd5' 
  AND token = 'tUsvFIMuwJgtPvH2Zdr9gJQ57D8ZhN060Qm4ARGaN3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}