SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f80884fb691f3fba9d55ca607a2f42a7bfcdd2813e7118c1c09b5377c8461c8a' 
  AND token = 'ZfOjad6XVDyLqBrlY9VOrpjzFv36+emQayS9o2nWMkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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