SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10ef582b1b235763b168e638b9e4082c5da2c5310257d92088da6fe966b07201' 
  AND token = 'V0QHWhXXN3iu8petHJ5gFhDu8CZhhJsO+XPYIJg2dcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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