SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e8f45f6559ba65036fcc0a58bfca1725fc376ee1505075a2975c44792d695cb' 
  AND token = 'sxVsW3QZ0RjJFNUXcBpejUEF9W7QFBVWa9odq8acSuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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