SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '94134404ef5e76a7c5f7338c25272968910ba68628960381f63e8b89bf722b2c' 
  AND token = 'c5QenYxN+zhdvZycJnrU4PF5L/obKssvrugLptW30mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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