SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c818ff8a20d9b254b4108dc5ad83c12cbcbc62402ba5422fb684db6eabd9fea9' 
  AND token = 'Hl7EQWLK92V7BMbv+ueL5HHWXDfEFi8sxoor4yRslpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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