SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3fb8c69e5ad094e18193229ce682925b74851187425ba434b660b1bd5c58484c' 
  AND token = 'uhzPxYK6v+S1WcVzEVw4htxifSFaXdePFloQ6ALRCYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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