SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44a80e18aa601b7a2863191c72f70ebf48a3223681a6e7975f27e4e0b8b3c4a0' 
  AND token = 'rCwHHFcUScXjvYytCWtOXB1MWhxF8p+BVVdlNrZdqGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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