SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '268ba9154be7322c716e3eb04902aa1a5a6880a5df241a4b3367b64001b83632' 
  AND token = 'IywCMjW+7b23J91Dwe+yxfhfKOyX2csZ1d/kdzThWDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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