SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a13ec3b6742f751e728bd0f37ee4595aa0850381bc576ac6d2071a1fcd60832a' 
  AND token = 'pn/e8DcQ5OYsZhTekIK9jyY35ohRV8wWdP0SErynphw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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