SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4a7c59c2b9ef0a9e7344807fbea8554736bc32de61a406abd37d4f892c4cd6c' 
  AND token = 'P5HdwmuBKMPzbbRAtlCbe9gx4hi6wN726o6D9KA3bHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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