SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e46d07943f88f9399a8b10bfa8c301021dcfc69b044c94d8b4a67bf84bbe35c' 
  AND token = 'C7otiWCWeYE7ePl0G05ACVFdFVwDVUNYRcG+WgpRRLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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