SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97853e7d9ef1cc561720df03fda00abd7b816569043ccfb477dcc7bc44d92495' 
  AND token = 'NqCVFdH+XVQbAY5FGYoL86Awcz20jm+YnSzwK2ZICaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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