SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84efd4cfb478f6d7ce022d9787195007535dd12b20ef0d17834f4dc923d622ab' 
  AND token = 'agbXjR0vJlI2/gKZ9/losKbmGISmCvQerXLlALYBaK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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