SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da2bf0966abfb2295b2216a1c16f0929f044d6a560fc2898d30adaf2b66aadd8' 
  AND token = 'xkL0AWQNQ1hD5pilbOM3Fos4C2NmEKj/ZRFIwd0Qi88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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