SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18c90d20e1dbf69d6399e10fd1b3208f986e5a2c271bdc2bf2e6257186d67e9c' 
  AND token = '595Fsqzenx8t48qO1m46vfON0F9INuOXugrH5G8ujXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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