SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44a911f00ca403990fcbdc78184cb5145ed94c9dd1ea5711c3ca54a9fe5b3060' 
  AND token = '8Z9HYjEOyLEoZXJlkmsXukQen4Lb7eZTP+D7pRufPwk=' 
  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"
    }
  }
}