SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34808572e91bcd3e69c2d5c1fe7ef82eaab612a904d3470f05155e7a4682f7be' 
  AND token = 'UXw3giCpTaX1KBDd8vYBXElbZKFGA0jHjOoZiGgZIfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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