SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f285b6f00e914cdd9a5b09d0a3c13bb96eefc4f73d138816787a0991feb12887' 
  AND token = 'DSkXj8s222Lu5VN39x249EraKtjzvOd5zWAZOADkNtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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