SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3d652239666cafd86ec4cc60ed15b2cbc054277fc2a0a307179ed06c339675a' 
  AND token = 'gnYOG9bALdGp2NR+2C1XxCEmaKrmuXAZLgZfxLzbaSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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