SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4dd655dd0fcde8fee3a4d4037b2b458f18d2039655c9a20c62ea517a8749f8d3' 
  AND token = 'oT2FISLmrXSFadQdYhGkaJiORRC108QyKyDzNAVfuZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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