SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4bef74810d888ff6d269f403ff9f2d941add70ba22ec5c7552118dc2792ea494' 
  AND token = 'xYs6LDJuBvwgfYbN0/nyBwHvzJLhSeud31xOIHLheBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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