SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c534b6c770f4feaae8d8a80dd9327bab40c5c9b93f8a566f579cf5fe501666b' 
  AND token = '/vQY+gxZ1HJTKql9t1S+RlxvS1IX77puXi2wnpnsmmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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