SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e4417243afe396534acdcaea928137fa0552ab8ca425e38bd810e8df010bb77' 
  AND token = 'QiUu7IARr05Y0mxnJv2r1JjDtQoRArm9vy24TgxWb6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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