SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb3102b9d65d3c91b7ace081af3b3687669ae37fd7c64b27ae7b1ed76db3a966' 
  AND token = 'YhO/ckB6U2HyW03tecrErDaXmcIigEXQogIjz2Lwwtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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