SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f0f0ff11b2c5d49f884bfeb182f71911331f4b5a7729c425c952c7239a7ba7d' 
  AND token = '0qcTEEXW3iyKkcCRDYQ8SPjcN/HYx8p/cWN1J0n9uvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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