SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17d7918b7f1d6b61e78fd37143bcb7c4d2d34451d880b771254e92276dd9fecc' 
  AND token = '3X60LlLvGVwhMoWs2hAIWU+zZ6FwSLIUEj/mt4llbUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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