SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5199c8961040e7af3f46af17d730a36afda27cb20676bbbf2bc0e0c3f770e5fb' 
  AND token = 'dppPUTaCoe8rXpPGLrR+0/0ADYFlb2o3U6vny/v7gHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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