SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a723022a9d83af11bc1dcdb8587c85aad1bac34effd6980ba181b32b5835049d' 
  AND token = 'iBxGKlomv8P5pmCIPtxqTkO/ThJYDSgkY705Krzur9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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