SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bfe169d24f8da710399108cbbed5206761a3d8f6f8dd4adf1fc3c03b49bfafb' 
  AND token = 'whc21+osUIwJbM5nLEFVmitKSAbaSQv18bKGXsaRXJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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