SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '159fe717f52f9cc54f410b4cbf3b748f643ef331b4fb74be82a1146b32d8ff29' 
  AND token = 'm43w6I7gWVDtHNvNR+QBrO3sfbsHpkdWBl19AFTMqys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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