SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1de7890b87c61890fb9907187825d176c128a6e2e42ecf0ef7c6caa58a529cb6' 
  AND token = 'qj8cEEM5SpmcCr3KlPj8twi9Qa3XId+8+OhVUzBvg4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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