SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9378752bd299c990a73eb25cfbc9bf4ae379f1899ce53773c8acd8e621ac483' 
  AND token = 'AprBo5U1p/yGov8qUzheHHJqpqoZWJ+3XK2MXtKQLZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}