SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9fa5f2d363d8c55205032cd8439514ca8c16ceaa68905bba2c352237b3327662' 
  AND token = 'HzHSqtTcLq7G3yz1aLpTSPrYBUy+b26PlJLyu+0wCng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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