SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c2ed9d812079877d372423b32cdce1b5573a6f4e81679617f87a774c7ec4bb9' 
  AND token = 'Ym+A7trDNFOL3V+++MSHsHXzTqOGHkUSpPsTH9GD9HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}