SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dffb13875e76bb75918395d37dbeaa3b2aa8294a7a5016772d4a4c127747c2e5' 
  AND token = 'smVlKYRA2Yv49FoUGWus0T0hZW0KFa0t3fovbv7APME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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