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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6c6fa15dbafbe731bd9c302e633972535e80cdc193b493c02449e510b5bbc0c0' 
  AND token = '3vu4hnKCdC1ui6GHeNOwinDA+mDSXQqYH5lUp7E+3Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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