SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a09914cf9dcca930606664281ee3843996dcc664179ba3c35539b9631ba92648' 
  AND token = 'KVWhYZLTsAbHlJq6SFtatwNJn+ZEyqhkSkWaRdOJTqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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