SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2e129a0d31d111b3d9f78f25b4ae64aaa88757f2db091d7013313b001d799ae' 
  AND token = '3x5X8vqiytKy3acArWaIHG7zZJc+vla3G45Rl0ozavA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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