SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61d4635285bd756874a90fb857bb3d5b44434d135173bec7d253024ff7289715' 
  AND token = 'mxnoVd5IO1WbmxK0w/+wojWi2aXbN48E+Q/vE3dZXVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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