SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cf9bf397e91292dcbcb71435c806ac232e903c538e90cf99ad27cfcb878bbff' 
  AND token = 'yKJGHUi/DaucMz8ysh0s3O1hqpuMfVaB6rU8jdV3TQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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