SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97e1cfb15facbe538b006bc7f036b84643e52dff681129c2212afd3f397031b3' 
  AND token = 'XrqoqkitcyS57ootGGxFVrzDKGsaE9jSMEuQm5uyfg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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