SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5853b54e656f3164cff0bc773605e8192bff1663108110fe5da11006902f2af2' 
  AND token = 'VtK6glg4gcj1sH8TLZEr7ru9p4JJe+uF/nBAomCBUBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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