SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ddddc6768f758a639c9b2b9336ad15a774832f3550305f07a13364ab7565bf' 
  AND token = 'oFq3C//nZ8dt28PJtx+FB7AVvUGVGV56bFzlCXLOosA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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