SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d4558d4b11e77f2bd343787dd2d324bd8be92e15a5656644e9af694d5193e4a' 
  AND token = 'VPe8m8hBE279ESdhqeCa+H57T05YobIFPiyZuS+PH6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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