SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba1d797fb729f9e5dda9450374f91a3df43eda30bbe100120513ca8ca4ca18a6' 
  AND token = '7jSRP9whN0CQ2kvw/3eCwM4XEq2UJgIJdaUgc/nNefY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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