SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a39e0a0725d5054310c59574d272c396274cd75b492ce4a86545cd7953338530' 
  AND token = 'BrCUHhW92MkkOi+5cjC0OvqDuyZ00/HpwPHxA7y6NQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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