SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b8598a8be03a29bbbc58e6a462149967e35f403216972d5931bb9c18212d65a' 
  AND token = 'JW4kYR74TxOeRHkKBVhnxyXYyGHBL/s3zZM06lDIg/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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