SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83eefe039bf4ae80cd17b98d66e0bebc58bd91cb8acefa044d9ec612a7e6fd12' 
  AND token = 'rwiX4vXLS5wg5ytzy42xnUnDmnDeQW3TuMIJdemk9uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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