Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8520f2cd1e6ed8fc03fbdd9aaa6e8081c0476702086c5b0fb6d247378ffc185' 
  AND token = 'nVV1jZUHR1cAqZ79NfAdw6AHeRTqXL5Y3mOQnShNaZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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