SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58509c22bd941244d6d2ed12945c4c0591e1177108ae349e7d3406f6babcef39' 
  AND token = '8gIZyRj1hXVTK7D4yYk0lr/kGxbvvqzMAW3HlpR6dxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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