SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33e5a28cc8d8f1c0adea5147d6195c1e1d0e1f12395024829d7d06299cc43aa4' 
  AND token = 'eCHz3jAJHBsSWZpbPvuYGKuPgcB/YW0pUhkAvpH8pgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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