SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f25e5e8fe23d69627d941107899f5767ec7cfbbe4e9683af80db2dfc04ae6b17' 
  AND token = 'Arb0wuTKsj6Y6mZNvf9sAQV2tfgIZXnVBY2yEshEyT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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