SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f3362e01b108d46b4f4f73c930307af7558e792fbdf65fa1cb5e046044732c5' 
  AND token = 'YtPq8WxT9UFziLr6qpSoHm1HhJAP4A+AimUZpzY44jU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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