SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca4fd0ad127e75812a2cb2baeb681de502088b45fb83d852b25c435633676cbe' 
  AND token = 'En/IKpbWOyazjNICGlY1JSdHmosvOoZEmk07/7WeLJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00083

JSON explain

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