SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a827345afa3af2c11f591f1b15e3ace9cb60fe008b9cd487d26a1b5a937d4454' 
  AND token = 's0EcGB26/RmnVGppQRwcOqn7iV8tBK2hIJy8bItXiL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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