SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3b691ea3acae363e694652108abb031ffeba3c86cad69f8ac29309bd3f9ce66d' 
  AND token = 'iWMbPVEQoMmgBv0ZW9YrWeWs8FH+OicAhl9OuIE28YQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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