SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9358dffde3584ac55f07f1f63a7482df67c6f9a63b5f5eab29b72753134a9036' 
  AND token = 'RZzlI2kYHQYwf2hvYzuxzVrNA9Be8UrocuNHp2sSH1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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