SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '062b71073bc5768523df50230c704dfc30dcab7f4feb1be217019432e7b53253' 
  AND token = 'BUbWaNUc4CO0LiIbfOUNc6gCCDZWxwzkOYf4031THYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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