SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3360c550cbdc54edd1d63ba503383209c467024c65ae1723c218b9ccd300e37' 
  AND token = 'nqXIDlvnrTLKDweo4xEqtnb46J3UFa8EBnUeZym+320=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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