SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe8d572c53a7d952ed9f512ec49068cbf0940f2c65dcbb66c11777912a13a38' 
  AND token = 'dEvdgwQP7SacK6nShTBYYyNpDXHJzwP5VHEwlNe9YVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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