SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2508f8099b2424cd8dfdbaed12cd1da8f291b8dbaf16476bb688c973795ecb15' 
  AND token = 'TGMSuMImQgCwy5FghgYoY+de+8hobaejxxVGrZOBDvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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