SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67dbc6a49eb84e6f07ba5003c64b002f89fa37f840e957c3616c7718c09c45f8' 
  AND token = 'FbMKjq7E7sxWLVof9Mc9oV4wwYCXZQ1bzduwycawJo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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