SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c0bffe8372b9fde93e62e88551b2c02826cc313fd57a98871e5a314cc1d92ae' 
  AND token = 'gDAZopxY6o9npNWi69JVZWf7MNxGpl2XKDKJpqTWV20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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