SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b2488117f5e3930b5e316fc23ae49833ac7b3194eca7015118a3b895112911b' 
  AND token = 'CqfvNKpeCKEFjcWyIiZBtlIDM8vYV0qdyxRm/3+/PhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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