SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '012e177173115c00731ade250bd294f4e109cb16a5394c5f27070e2fc87b916b' 
  AND token = 'E3vU03Y8zFCQRWsmcsSKQ4Xa+hfy/mFxz6A5nqTwkXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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