SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e80b23e6002450a5be0b962d45ec1bb7c1cbf778b5d27da09b793b171c1c5e0' 
  AND token = 'AS70MzBSuyeDGiQP8QSIQAcsRlFBgBcdkSVhCbozmsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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