SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7b3d23e41994ce70925c132e712f8d3a4298ef8b262c0ef82613a356c89b819c' 
  AND token = '5Dy0c3PuLvYN3FyW8B0LOrp9lq8SqDEGPMY2YNJwo4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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