SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b40187d64c4f0c21988ba2935531224aa9ca8b75f6deba3eaecc8566e75dd82' 
  AND token = 'rHkp51wsJ3scaMT4F8jUzepNWAMTn/A8lxhrOje7NG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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