SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd62e408dff16c3225998b9e8d6953e518996787382e3c645c3faa3310563f6e5' 
  AND token = 'J2W3f8XOTbHEiKtzrUcgNlOMC5mxBs5q3FMgvHsCKaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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