SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a9bf3043d65f691599938ab387fbd70f08bac02eb25971d5c1c5ebdcb05c9cc' 
  AND token = 'ZrWt+GyB5W8cUfbRlHfGbQPL/jSNlZn1ekz2lTZ6GBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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