SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db8f37632129c12158e6956d18ab67b82316b79a87d9eb78adbe4b463c9d89d3' 
  AND token = '5cadFHYHoaBMsmRLc41A88UKA3rXcs7s8s9rXLnO7Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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