SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc7e4c6a39bac40d1bb86da13a28cf30b694f661a2b255f3e3aa0b3658bb2f8' 
  AND token = '1gu/OW2X4tQRJzdcwLSLDbtWI9WUvY8sJjhibKBTojI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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